As you read this, you're probably thinking . . . "Won't this guy ever stop with the polyurethane adhesive stuff ?" Once again the "Glueru" brings a tip which may take some of the frustration from glue-ups in the shop or on the job site.
The following tip will work for most any clamp, but is especially useful for bar and pipe clamps which present large surfaces on the clamp "faces". What results will be clamps with softer faces which significantly reduces the likelyhood of marring of the workpieces.
1. Remove any grease, oil or other substance from the surface of the clamp faces. Denatured alcohol, acetone or other quick evaporating solvent will work fine for this step.
2. Cut wood pads to closely (doesn't have to be exact, we're not building a piano) match the size and shape of the clamp faces. I use 1/4" pine plywood scraps for my pads, but any wood should work fine as long as you keep in mind that you are trying to eliminate marring of the workpiece and that softer woods will serve better than harder woods. Clean or wipe any dust from the pads.
3. Prepare to glue the pads to the metal clamp faces by deciding which face of the pads will receive the adhesive. Lightly dampen the pads where the adhesive is to be applied and apply just enough polyurethane adhesive to cover the surface of the pads.
4. Position the clamp you are working with so that the clamping faces are relatively close to each other and place a pad on each clamping face. Be sure there is no residual adhesive on the face of the pads or you will not be able to seperate the clamp faces. Slide or otherwise adjust the clamp faces so they are just touching and adjust the clamps so that the pressure (face to face) is sufficient to hold the pads in place as the adhesive cures.
The pads I have installed on all of my clamps using the above methods have stayed put for more than two years. If any pads should become marred they can be removed with an old chisel or similar tool, after which new pads can be installed as before.
C.E. "Chuck" Ring